Buoyant attachment for oars



Nov. 9, 1954 N. H. BERLEW 2,693,605

BUOYANT ATTACHMENT FOR OARS Filed Sept. 16, 1952 INVENTOR NELSON HENRY BERLEW BY @MMFN- ATTORNEY United States Patent Ofiice iatented Nov. 9, 1954 1 2,693,605 BUOYANT ATTACHMENT FOR OARS Nelson Henry Berlew, Harford, N. Y. Application September 16, 1952, Serial No. 309,917 2 Claims. (Cl. 9-24) The present invention relates to oars, paddles and analogous implements used in the hand propulsion of small watercraft, such as row boats and canoes.

More particularly the invention provides a buoyant implement of the class described, hereinafter called generically an oar, by which the oar will float and be capable of sustaining, or of assisting in sustaining, the weight of a person in water.

Generally speaking, the invention comprises an attachment containing a sealed air chamber which can be secured to the shaft of an oar in such a position that it will not interfere with normal use of the oar but will provide enough buoyancy to serve as a life preserver In case of an emergency.

A preferred embodiment of the invention is depicted in the accompanying drawing in which:

Figure 1 is a side elevational view of an oar showing the attachment applied to the oar shaft;

Fig. 2 is a side elevational view of the attachment, illustrated on a relatively enlarged scale;

Fig. 3 is a cross sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a top plan view of one of the sheets or plates which form the side walls of the attachment air chamber; and

Fig. 5 is a side elevational view of a length of tubing used in fabricating the attachment.

Referring to the drawing, a more or less conventional type of oar, as used in connection with row boats, is illustrated at 1, and includes a shaft 2 having at one end a handle portion 3 and having at its other end a blade portion 4. Any usual type of oar lock is provided on the shaft, as indicated at 5.

The buoyant chamber attachment comprises a relatively thin and wide body of flat or narrow cross section, tapering in width so as to present the somewhat semicircular plan appearance shown in Figs. 1 and 2. The body is conveniently made by severing a tube 6, shown in Fig. 5, of light metal stock such as aluminum or an aluminum or magnesium alloy, diametrically along its length to provide two identical half round trough-like framing members or framing member sections, designated respectively 7 and 8. The tubing diameter is selected to equal that of the oar shaft to which the device is intended to be applied.

One of the members or sections, for example the section 7, is bent to the substantially semi-circular contour best shown in Fig. 2, with the extreme end portions 9, 9 left in their original lengthwise alignment. These end portions are slightly expanded so that their internal diameter equals their original external diameter and thus the concave surface of the outer section is identical in cross sectional shape and size to the convex surface of the inner section, and the bent section is then superposed on the straight section and securely attached thereto as by welding, soldering or the equivalent, to provide the relationship best shown in Fig. 2, in which the end portions of the straight section 8 project slightly beyond the adjacent ends of the curved section 7.

To each side of the framework thus formed there is securely attached a substantially semi-circular sheet or plate 10 which conforms in peripheral or perimetric shape to the straight line base and outer or top curvature of the framework, and these sheets are hermetically sealed at their margins to the metal of the framework. The attachment can be made by welding, soldering, brazing or the like if, as is preferred, sheets 10 are formed of metal. However, they may be made of rigid durable strong plastic, in which case they are attached to the framework by any appropriate adhesive or analogous bonding or vulcanizing material or means.

It will be recognized that in some cases, depending on the degree of overlap of each sheet 10 on the framework, some slight offset of the sheets may be required at the zones where the curved portions of the section 7 merge with the straight end portions thereof, designated 11 in Fig. 2. The sheets can, of course, be distorted to the necessary offset relationship, or the tapering space at the ends of the sheets may be filled with Weld metal or other sealing material.

There is thus provided a relatively wide and thin chamber containing air, having along its base a half round open channel which more or less accurately fits the outer surface of the oar shaft. The device is applied to the shaft by nesting its channel base on the shaft and securing it thereto by any convenient means, such as the pipe clamps 12, 12 shown in Fig. 1.

In order to diminish wind resistance and avoid interference with the rowing or'paddling operation, I prefer to mount the attachment on the oar in such a position that its wider dimension, which may be considered its plane, extends right-angularly to the flat surface of the blade 4, as shown in Fig. 1.

With the device thus attached, the oar or paddle can be used in the normal manner for propelling a boat. The attachment, being made of light metal, plastic or the like and providing a relatively large air chamber, is highly buoyant, and adds to the oar enough increased buoyancy to support or substantially support a person in deep water grasping the oar.

It is to be understood that the specific material of which the attachment is made forms no part of the present invention. It is important that the material be durable, reasonably rigid, and quite light. Aluminum and magnesium alloys are consequently suitable, but they are presently more costly than certain plastics that are available commercially in both tubular and sheet forms and which I have found entirely satisfactory and acceptable for forming the framing member sections 7 and 8 and the sheets or plates 10. The appended claims are therefore to be read without any limitation, express or implied;l to any particular material except where otherwise state The structure thus disclosed in a preferred form of embodiment may be modified within the broad principles of the invention as by forming in the chamber a division or subdivision hermetically sealed from the rest of the chamber and closed by a door, thus providing a compartment in which a small quantity of food or drink or a signal device may be encased. Other and further modifications and amplifications of the basic structure shown by the drawing will readily suggest themselves to persons skilled in the art.

I claim:

1. An attachment for an oar shaft of rounded cross section comprising an inner framing section of rigid material of straight half-tubular shape adapted to nest against a side of the shaft, an outer framing section of rigid material of half-tubular shape having aligned straight end portions connected by an outwardly curved median portion disposed in the same plane as the inner section with the median portions of the sections spaced apart and with their respective end portions engaged with and connected to each other, and a pair of rigid fiat sheets having peripheral shapes corresponding to the shape of the openmg between the spaced apart portions of the pair of assembled sections and attached in airtight relation to opposite sides thereof to provide therewith a buoyant air chamber.

2. An attachment as claimed in claim 1 in which the concave surface of the outer section is identical in cross sectional shape and size to the convex surface of the mner section and the sheets are substantially parallel. 

